1. Field of the Invention
This invention relates to contact method for the physical and/or chemical processing of substances in multiphase flow systems. The contacting occurs between two or more cocurrent flows of separate phases, e.g. gas and liquid phases or different liquid phases, either of which may also include a solid phase, or liquid and solid phases. The advantages of the invention thus are applicable in a broad field.
2. Description of the Prior Art
In the field of gas purification methods and apparatus, it has been known to clean a contaminated gas containing noxious fumes, chemical gases and/or dust particles, such as flue gas, stack gas, chemical process gases, industrial air exhausts and the like, by passing flows of the gas and a scrubbing liquid cocurrently through contacting devices of various types for wetting the dust particles therein for collection and for solubilizing other of such contaminants into the scrubbing liquid. Among the systems known is a type in which a gas is passed tangentially into a cylinder through charging slits and the liquid is drawn upward along the inner wall of the cylinder by utilizing the whirling and ascending force of the gas, and the liquid so drawn into the cylinder is atomized by the gas entering the cylinder. In one such system, described in Miura U.S. Pat. No. 3,651,619, the gas to be treated is charged into a cylinder through lower slits of a cylinder having a set of upper and lower slits formed in the tangential direction in the side wall thereof, and a liquid at the bottom of said cylinder is drawn by the whirling and ascending force of the gas to cause it to rise in the form of liquid film along the inner wall of the cylinder, which liquid is then atomized by the gas entering from the slits, thus centrifugally separating the liquid containing impurities due to the whirling force of the gas when the gas is discharged from the upper slits. Devices of this type have various disadvantages. The upwardly flowing gas is required to elevate the liquid and move it in the upward direction counter to the force of gravity and must expend considerable energy for so doing, thereby causing loss of pressure and expansion of the gas in passing through the apparatus, generally requiring the use of costly gas compression equipment and substantial expenditures for the power therefor. Also in ascending cocurrent mixed phase systems, the force of gravity tends to cause the heavier phase to become separated from the lighter phase. Furthermore, in devices of this type the weight ratio of the liquid to the gas flow is limited, the maximum quantity of liquid flow being dependent on the velocity of the gas flow.